1. Field of the Invention
This invention relates to pressure compensated hermetically sealed transmission systems. Accordingly, the general object of the invention is to provide new and improved systems of such character.
2. Description of the Prior Art
.Iadd.The prior art shows a wide variety of hermetically sealed transmission means, in which a mechanical transmission means is sealed by a bellows or other diaphragm between a movable element of the transmission means and a surrounding wall. Although such seals have been known at least since 1938, official and private searches prior to this reissue application have not uncovered any suggestion of making the diaphragms for such devices more reliable by equalizing the pressures on the two sides thereof. .Iaddend.
In accordance with preliminary novelty searches performed on behalf of the applicant, specifically for the following concepts: (1) Bearings on both sides of a wobble plate, wherein as the wobble plate rocks, the output shaft rotates; and (2) .[.bellow.]. .Iadd.bellows .Iaddend.systems with the foregoing, with pressure feedback through an upper loop to insure equal pressure on both sides of the bellows, the following patents of interest were found:
U.S. Pat. No. 2,119,955--LITTON PA1 U.S. Pat. No. 2,137,303--NELSON PA1 U.S. Pat. No. 2,770,139--SHEN et al PA1 U.S. Pat. No. 2,771,787--RANSON PA1 U.S. Pat. No. 2,779,197--EMBREE PA1 U.S. Pat. No. 3,010,887--BAUMGARTEN et al PA1 U.S. Pat. No. 3,028,761--COLE, JR. PA1 U.S. Pat. No. 3,049,931--LANG, JR. et al PA1 U.S. Pat. No. 3,424,017--HASQUENOPH et al PA1 1. "Look at Forged Valves for Nuclear" by A. K. Velan .Iadd.".Iaddend.Power.Iadd." .Iaddend.September 1973 pp. 44-45 PA1 2. "Operating Experience with Valves in Nuclear Power Plants," by K. H. Arriens. .Iadd.".Iaddend.Combustion.Iadd." .Iaddend.February 1974 pp. 31-36. PA1 French Pat. No. 1,099,067 (1955) in which several diaphragms were used, various fills between them being suggested, but with no mention of pressurizing a fluid fill.
Litton U.S. Pat. No. 2,119,955 and Lang, Jr. et al., U.S. Pat. No. 3,049,931 combine the rocking type of action in a coupling with sealing means and in the case of the Litton patent with a bellows type of seal.
Cole, Jr. U.S. Pat. No. 3,028,761 also discloses use of wobble plates with bellows for hermetic sealing.
Nelson, U.S. Pat. No. 2,137,303, discloses rotating shafts with a bellows type of seal.
Baumgarten et al., U.S. Pat. No. 3,010,887, also discloses rotation of a shaft and the use of bellows seals.
Embree, U.S. Pat. No. 2,779,197, discloses bellows as seals with pressure compensation.
The remaining U.S. .[.patens.]. .Iadd.patents .Iaddend.set forth above are further examples of bellows used as seals in rotary systems.
Other articles of interest include the following two publications:
.[.No prior art was found suggesting the use of equalized pressure bellows sytems with rotating shafts..].
.Iadd.Among patents found by the Examiner before allowing the original patent here being reissued, the most interesting was:
It is known to provide some degree of compensating pressure around a bellows that is pumping rather than sealing a transmission means, "to keep the differential pressures below the critical limit of the bellows". .Iaddend.